Just a quality of life feature set for your Roll20 Character Sheet
// ==UserScript==
// @name Better Roll20 - CS
// @namespace http://tampermonkey.net/
// @version 1.2
// @description Just a quality of life feature set for your Roll20 Character Sheet
// @author Mathy
// @match https://www.tampermonkey.net/scripts.php?ext=dhdg&updated=true&version=5.2.2
// @match https://app.roll20.net/editor/character/*
// @icon https://www.google.com/s2/favicons?sz=64&domain=tampermonkey.net
// @grant none
// @license MIT
// ==/UserScript==
(function() {
'use strict';
document.querySelector('#dialog-window > div > ul > li.active > a').style.background = "red"
console.log("Loading Better Roll 20 - CS...")
const coinInputs = document.querySelectorAll(".equipment .money .coin input")
coinInputs.forEach((input) => {
input.addEventListener('keydown', autoCalculate);
})
const healthInput = document.querySelector("input[name=attr_hp]")
healthInput.type = "text"
healthInput.addEventListener('keydown', autoCalculate)
function autoCalculate(e) {
if (e.key === 'Enter') {
const newValue = calculate(e.target.value)
e.target.value = newValue
}
}
window.calculator = calculate
// math eval from: https://gist.github.com/tkrotoff/b0b1d39da340f5fc6c5e2a79a8b6cec0
const minus0Hack = value => (Object.is(value, -0) ? "-0" : value)
const operators = {
"+": {
func: (x, y) => `${minus0Hack(Number(x) + Number(y))}`,
precedence: 1,
associativity: "left",
arity: 2
},
"-": {
func: (x, y) => `${minus0Hack(Number(x) - Number(y))}`,
precedence: 1,
associativity: "left",
arity: 2
},
"*": {
func: (x, y) => `${minus0Hack(Number(x) * Number(y))}`,
precedence: 2,
associativity: "left",
arity: 2
},
"/": {
func: (x, y) => `${minus0Hack(Number(x) / Number(y))}`,
precedence: 2,
associativity: "left",
arity: 2
},
"%": {
func: (x, y) => `${minus0Hack(Number(x) % Number(y))}`,
precedence: 2,
associativity: "left",
arity: 2
},
"^": {
// Why Math.pow() instead of **?
// -2 ** 2 => "SyntaxError: Unary operator used immediately before exponentiation expression..."
// Math.pow(-2, 2) => -4
// eslint-disable-next-line prefer-exponentiation-operator, no-restricted-properties
func: (x, y) => `${minus0Hack(Math.pow(Number(x), Number(y)))}`,
precedence: 3,
associativity: "right",
arity: 2
}
}
const operatorsKeys = Object.keys(operators)
const functions = {
min: {
func: (x, y) => `${minus0Hack(Math.min(Number(x), Number(y)))}`,
arity: 2
},
max: {
func: (x, y) => `${minus0Hack(Math.max(Number(x), Number(y)))}`,
arity: 2
},
sin: { func: x => `${minus0Hack(Math.sin(Number(x)))}`, arity: 1 },
cos: { func: x => `${minus0Hack(Math.cos(Number(x)))}`, arity: 1 },
tan: { func: x => `${minus0Hack(Math.tan(Number(x)))}`, arity: 1 },
log: { func: x => `${Math.log(Number(x))}`, arity: 1 } // No need for -0 hack
}
const functionsKeys = Object.keys(functions)
const top2 = stack => stack[stack.length - 1]
/**
* Shunting yard algorithm: converts infix expression to postfix expression (reverse Polish notation)
*
* Example: ['1', '+', '2'] => ['1', '2', '+']
*
* https://en.wikipedia.org/wiki/Shunting_yard_algorithm
* https://github.com/poteat/shunting-yard-typescript
* https://blog.kallisti.net.nz/2008/02/extension-to-the-shunting-yard-algorithm-to-allow-variable-numbers-of-arguments-to-functions/
*/
function shuntingYard(tokens) {
const output = new Array()
const operatorStack = new Array()
for (const token of tokens) {
if (functions[token] !== undefined) {
operatorStack.push(token)
} else if (token === ",") {
while (operatorStack.length > 0 && top2(operatorStack) !== "(") {
output.push(operatorStack.pop())
}
if (operatorStack.length === 0) {
throw new Error("Misplaced ','")
}
} else if (operators[token] !== undefined) {
const o1 = token
while (
operatorStack.length > 0 &&
top2(operatorStack) !== undefined &&
top2(operatorStack) !== "(" &&
(operators[top2(operatorStack)].precedence > operators[o1].precedence ||
(operators[o1].precedence ===
operators[top2(operatorStack)].precedence &&
operators[o1].associativity === "left"))
) {
output.push(operatorStack.pop()) // o2
}
operatorStack.push(o1)
} else if (token === "(") {
operatorStack.push(token)
} else if (token === ")") {
while (operatorStack.length > 0 && top2(operatorStack) !== "(") {
output.push(operatorStack.pop())
}
if (operatorStack.length > 0 && top2(operatorStack) === "(") {
operatorStack.pop()
} else {
throw new Error("Parentheses mismatch")
}
if (functions[top2(operatorStack)] !== undefined) {
output.push(operatorStack.pop())
}
} else {
output.push(token)
}
}
// Remaining items
while (operatorStack.length > 0) {
const operator = top2(operatorStack)
if (operator === "(") {
throw new Error("Parentheses mismatch")
} else {
output.push(operatorStack.pop())
}
}
return output
}
/**
* Evaluates reverse Polish notation (RPN) (postfix expression).
*
* Example: ['1', '2', '+'] => 3
*
* https://en.wikipedia.org/wiki/Reverse_Polish_notation
* https://github.com/poteat/shunting-yard-typescript
*/
function evalReversePolishNotation(tokens) {
const stack = new Array()
const ops = { ...operators, ...functions }
for (const token of tokens) {
const op = ops[token]
if (op !== undefined) {
const parameters = []
for (let i = 0; i < op.arity; i++) {
parameters.push(stack.pop())
}
stack.push(op.func(...parameters.reverse()))
} else {
stack.push(token)
}
}
if (stack.length > 1) {
throw new Error("Insufficient operators")
}
return Number(stack[0])
}
/**
* Breaks a mathematical expression into tokens.
*
* Example: "1 + 2" => [1, '+', 2]
*
* https://gist.github.com/tchayen/44c28e8d4230b3b05e9f
*/
function tokenize(expression) {
// "1 +" => "1 +"
const expr = expression.replace(/\s+/g, " ")
const tokens = []
let acc = ""
let currentNumber = ""
for (let i = 0; i < expr.length; i++) {
const c = expr.charAt(i)
const prev_c = expr.charAt(i - 1) // '' if index out of range
const next_c = expr.charAt(i + 1) // '' if index out of range
const lastToken = top2(tokens)
const numberParsingStarted = currentNumber !== ""
if (
// 1
/\d/.test(c) ||
// Unary operator: +1 or -1
((c === "+" || c === "-") &&
!numberParsingStarted &&
(lastToken === undefined ||
lastToken === "," ||
lastToken === "(" ||
operatorsKeys.includes(lastToken)) &&
/\d/.test(next_c))
) {
currentNumber += c
} else if (c === ".") {
if (numberParsingStarted && currentNumber.includes(".")) {
throw new Error(`Double '.' in number: '${currentNumber}${c}'`)
} else {
currentNumber += c
}
} else if (c === " ") {
if (/\d/.test(prev_c) && /\d/.test(next_c)) {
throw new Error(`Space in number: '${currentNumber}${c}${next_c}'`)
}
} else if (functionsKeys.includes(acc + c)) {
acc += c
if (!functionsKeys.includes(acc + next_c)) {
tokens.push(acc)
acc = ""
}
} else if (
operatorsKeys.includes(c) ||
c === "(" ||
c === ")" ||
c === ","
) {
if (
operatorsKeys.includes(c) &&
!numberParsingStarted &&
operatorsKeys.includes(lastToken)
) {
throw new Error(`Consecutive operators: '${lastToken}${c}'`)
}
if (numberParsingStarted) {
tokens.push(currentNumber)
}
tokens.push(c)
currentNumber = ""
} else {
acc += c
}
}
if (acc !== "") {
throw new Error(`Invalid characters: '${acc}'`)
}
// Add last number to the tokens
if (currentNumber !== "") {
tokens.push(currentNumber)
}
// ['+', '1'] => ['0', '+', '1']
// ['-', '1'] => ['0', '-', '1']
if (tokens[0] === "+" || tokens[0] === "-") {
tokens.unshift("0")
}
return tokens
}
function calculate(expression) {
const tokens = tokenize(expression)
const rpn = shuntingYard(tokens)
return evalReversePolishNotation(rpn)
}
})();